Proximal Supply in Loess Deposition of the Chinese Loess Plateau

Abstract

AbstractPrevious studies suggest that the northeastern Tibetan Plateau has been the major source area for the Chinese Loess Plateau (CLP); this contribution was used to prove that the Yellow River played a dominant role in transporting the materials from the northeastern Tibetan Plateau, making them available for the CLP. Accordingly, the proximal North China Craton is considered to have increased supply potential of dust to the CLP further eastward. However, the origin of the eastern CLP and the relationship between loess and proximal river sediments have never been systematically studied, which prevents us from working out the surface process between source and sink. In this study, we conducted U–Pb dating and analyses of the grain morphologies of detrital zircons and heavy mineral assemblages on the upper Quaternary loess and riverbed sediments on the eastern and central CLP. We also built a data set (n = 48,161) of the zircon U–Pb ages of the Quaternary loess, deserts, and potential source areas. Our results show that most loess samples on the eastern CLP were strongly affected by the North China Craton. The dust supply ability of rivers to loess is very limited. Along the dust transport path, the proximal mountains, rivers and loess can all provide dust for loess deposition. Our findings emphasize the important role proximal supply has played in the evolution of the CLP since at least the late Neogene, for example, the northeastern Tibetan Plateau for the western and central CLP, and the North China Craton for the eastern CLP.